Field of the Invention
The present invention relates to an electrophotographic photosensitive member, a process cartridge and an electrophotographic apparatus each including an electrophotographic photosensitive member and a process for producing an electrophotographic photosensitive member.
Description of the Related Art
In recent years, an electrophotographic photosensitive member (organic electrophotographic photosensitive member) including a support, an undercoat layer on the support and a photosensitive layer on the undercoat layer has widely been used.
In the undercoat layer, a metal oxide particle and an organic compound are often contained in order to stabilize electrical properties and suppress image defects.
Japanese Patent Application Laid-Open No. 2006-221094 discloses a technology in which a metal oxide particle and an acceptor compound such as an anthraquinone compound are contained in the undercoat layer.
The acceptor compound can have a group that can react particularly with the metal oxide particle. It is described that image defects such as a ghost phenomenon and fogging are suppressed by imparting an acceptor property to the undercoat layer with the acceptor compound contained in the undercoat layer.
Japanese Patent Application Laid-Open No. 2013-137518 discloses a technology that suppresses a ghost phenomenon with a metal oxide particle and a benzophenone compound having a hydroxy group or an amino group each contained in the undercoat layer. It is inferred that an organic compound having such a substituent interacts with the metal oxide particle to make the acceptance and donation of electrons between metal oxide particles in the undercoat layer or from a photosensitive layer to the undercoat layer smooth.
However, in the case where an electrophotographic photosensitive member including an undercoat layer containing a metal oxide particle is placed under a high-temperature and high-humidity environment to absorb moisture, repetitive use of the electrophotographic photosensitive member makes the electrical properties deteriorated in some cases. Although it is anticipated that the constitution of the prior technology enhances the effect of acceptance and donation of electrons of the metal oxide particle, an electrophotographic photosensitive member having further stable electrical properties even under various environments is required in the trend toward higher speed operation and higher image quality in electrophotographic apparatuses in the future.